Hovering and gliding multi-wing flapping micro aerial vehicle

Abstract

Multi-wing hovering and gliding flapping Micro Air Vehicles (“MAV”) are disclosed. The MAV can have independent wing control to provide enhance energy efficiency and high maneuverability. Power to each wing can be controlled separately by varying the amplitude of the wing flapping, the frequency of the wing flapping, or both. The flapping frequency can be controlled such that it is at or near the natural frequency of the wings for improved energy efficiency. The wings can be controlled by a gear train, coil-magnet arrangement or many other actuation systems that enable variable frequency flapping, variable amplitude flapping, or a combination of both. The gear train mechanism provides gyroscopic stability during flight. The wing flapping can include a rotation, or feathering motion, for improved efficiency. The wings can be transitioned between flapping flight and fixed wing flight to enable gliding and hovering in a single configuration.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application Ser. Nos. 61 / 443,914, filed 17 Feb. 2011; 61 / 466,204, filed 22 Mar. 2011; and 61 / 481,500, filed 2 May 2011; and 61 / 481,484, filed 2 May 2011. All of the above-referenced applications are incorporated herein by reference in their entireties as if fully set forth below.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The invention relates to the field of aerial vehicles, and in particular, to micro aerial vehicles with flapping wings.[0004]2. Description of the Related Art[0005]Micro aerial vehicles (MAVs) are small, unmanned aerial vehicles that are typically flown by remote control. MAVs can be, for example and not limitation, small airplanes, helicopters, or ornithopters. Although there is no definite list of qualifications that a vehicle must meet to be considered an MAV, the Defense Advanced Research Projects Agency (DARPA) requires that a particular aer...

AI Technical Summary

Benefits of technology

[0029]Embodiments of the present invention can further comprise a control gear set located at each of the four or more wings. Each of the control gear sets can comprise, for example, a ring gear movable between a first position and a second position and one or more spider gears located inside the ring gear and in geared engagement with the ring gear. In some embodiments, a first spider gear of the one or more spider gears can comprise a drive pin for converting rotary motion to reciprocating motion. In this configuration, when the ring gear is in the first position, the reciprocating motion of the drive pin can be substantially vertical, while when the ring gear is in the second position, the reciprocating motion of the drive pin can be substantially horizontal. In other words, rotating the ring gear from the first position to the second position enables the reciprocating motion of the drive pin to transition from substantially vertical motion to substantially horizontal motion (and combinations thereof between the first position and the second position).

[0030]In some embodiments, each control gear set can further comprise a flapping actuator pivotally coupled to the central chassis section and in slideable engagement with the drive pin. In this configuration, rotating the ring gear in a first direction can move the reciprocation motion of the drive pin on the first spider gear in the horizontal direction, reducing the amplitude of the motion of the flapping actuator, while rotating the ring gear in a second direction can move the reciprocation motion of the drive pin on the first spider gear in the vertical direction, increasing the amplitude of the motion of the flapping actuator. In some embodiments, when the ring gear is in the second position, the motion of the flapping actuator can be reduced to approximately zero amplitude to provide fixed-wing, or fixed-wing like flight. In some embodiments, each control gear set can further comprising a phase gear, which can be in geared engagement with the ring gear, and can rotate the ring gear from the first position to the second position.

[0031]In other embodiments, the drive system can further comprise one or more transfer gears for transferring power from the one or more drive motors to each of the control gear sets. In a preferred embodiment, the axis of rotation of the transfer gears, the ring gears, and the spider gears is about a first axis to provide gyroscopic stability about the first axis and a second axis and the axis of rotation of the motor is about a third axis to provide gyroscopic stability about the second axis and the third axis. In this manner, the drive system can provide gyroscopic stability in all three axes.

[0032]Embodiments of the present invention can further comprise a method of providing flight control for a flying machine. The method can comprise, for example, providing a flying machine with four or more flapping wings, each of the wings comprising independently controllable amplitude, independently controllable frequency, or both, and varying the amplitude or frequency of the flapping of each of the four or more wings to vary the lift provided by each of the wings. In some embodiments, the method can also comprise reducing the amplitude of the flapping of all of the four or more wings to zero, which can provide fixed wing flight. During fixed wing flight, it may be desirable to intermittently flap one or more of the wings to increasing the lift of one or more of the wings during fixed wing flight to provide energy savings and / or flight control.

[0033]In some embodiments, the four or more wings can be flapped at substantially the same amplitude, substantially the same frequency, or a combination thereof such that total lift, total thrust, or both produced is same for each wing to provide hovering flight. Varying the amplitude, the frequency, or both between a first set of wings, located proximate a rear portion of the flying machine, and a second set of wings located proximate a front portion of the flying machine, can be used to control pitch. Similarly, varying the amplitude, the frequency, or both between a first set of wings, located proximate a right portion of the flying machine, and a second set of wings located proximate a left portion of the flying machine, can provide roll control. Finally, varying the amplitude, the frequency, or both between a first set of wings, comprising a first wing located proximate a right, rear portion of the flying machine and a second wing proximate a left, front portion of the flying machine and a second set of wings, comprising a first wing located proximate a right, front portion of the flying machine and a second wing proximate a left, rear portion of the flying machine, can provide yaw control. In some embodiments, the amplitude and / or the frequency of the four or more wings can be varied to vary the overall lift provided by the four or more wings.

Problems solved by technology

DARPA also places limits on, among other things, the range, endurance, operational altitude, maximum speed, maximum payload, and cost of manufacture.

Unlike conventional aerial vehicles, however, an MAV's small size and maneuverability can make it difficult to detect.

Fixed-wing MAVs cannot hover or fly backwards, however, and have a limited ability to fly at slow speeds.

Rotary-wing MAVs are generally inefficient, however, and so their maneuverability comes at the cost of shorter flight time and lower payload capacities.

The inefficiencies of presently known MAVs are due, at least in part, to aerodynamics.

These variances can cause inefficiencies if larger vehicles are simply scaled down to MAV size, or smaller.

For this reason, designing MAVs that can efficiently fly in this regime represents a unique and difficult challenge to design engineers.

In general, however, conventional VTOL capable vehicles do not efficiently scale down to the small sizes of MAVs.

This means that large VTOL capable vehicles cannot simply be reduced to MAV size and maintain high flight efficiencies.

Birds and insects therefore have unmatched maneuverability, speed, and agility.

However, all of these models lack appreciable flight time, appreciable payload capacity, the ability to fly in six degrees of freedom (i.e., hovering and VTOL capabilities).

The use of two wings limits the lifting power that can be generated while staying within the MAV sizing parameters.

In addition, in prior designs, the wings were not independently controlled.

Because the wings were not independently controlled, modifying the flapping amplitude and / or frequency of each individual wing was not possible.

Unlike many birds and insects, current designs do not utilize resonance to reduce the amount of energy needed to flap the wings.

This can be an inefficient way to produce and / or modify thrust.

For these reasons, known MAVs with flapping wings are inefficient, have low lifting power, and are overly complex.

Moreover, the inefficiencies and low lifting power associated with these MAVs require that they either have small power supplies that exhaust quickly, or be tethered to an external power supply.

Accordingly, while engineers have modeled MAVs after some birds and insects, there are many designs that have not yet been attempted.